Photosynthetic organisms such as microalgae are being utilized to produce biodiesel by converting organic molecules to lipids that can then be converted to biodiesel. These photosynthetic organisms are far from monolithic. Biologists have categorized microalgae in a variety of classes, mainly distinguished by their pigmentation, life cycle and basic cellular structure. The four most important (at least in terms of abundance) are: The diatoms (Bacillariophyceae), green algae (Chlorophyceae), blue-green algae (Cyanophyceae) and the golden algae (Chrysophyceae).
Microalgae are a primitive form of plants. Microalgae grow in aquatic environments. Microalgae, like higher plants, produce storage lipids in the form of triacyglycerols (TAGs). Although TAGs could be used to produce of a wide variety of chemicals, in here we will focus on the production of fatty acid methyl esters (FAMEs), which can be used as a substitute for fossil-derived diesel fuel. This fuel, known as biodiesel, can be synthesized from TAGs via a simple transesterification reaction in the presence of acid or base and methanol. Biodiesel can be used in unmodified diesel engines, and has advantages over conventional diesel fuel in that it is renewable, biodegradable, and produces less SOx and particulate emissions when burned.
The algal membrane resulted from the extraction of lipids has been proposed for different uses such as animal feed or plant nutrients. When unconventional algal feed such as sewage are used for the microalgae growth, the membrane cannot be easily utilized as animal feed without further treatment.
This invention is disclosing a process to convert the algae membrane to carbon nanotubes. Conventional methods for production of carbon nanotubes include chemical vapor deposition, laser ablation and arc discharge methods. All of these methods require pure carbon source for the production of carbon nanotubes (see Graham et al. U.S. Pat. No. 7,635,867 and Liu et al. U.S. Pat. No. 7,625,544)
This invention utilizes the algae membrane as a source for nanotubes production.